Frederic, meanwhile, got a more extensive look last season, suiting up for 15 NHL games over three stints with Boston. Playing mostly as the B's third-line center, the 21-year-old did not register a point, but gained valuable experience, some of which came from simply being around the team during its run to the Stanley Cup Final.
The St. Louis native - along with Senyshyn and the rest of the Black Aces - was with the Bruins throughout the postseason, and while he didn't make it into a game, he is hoping to carry all that he learned into his second full professional season.
"The playoffs were a great experience," said Frederic, who has 19 goals and 33 points in 68 games for Providence over the last two seasons. "It's bitter with the last game, but we have a great team and I think we have a chance to take a run at it again.
"I'm just excited to get going. I've been working hard and just ready to get this all started…I've been training back home, took a little break and then went back at it. I feel really good."
While roster spots may be limited as the Bruins return much of the roster that got them to within a game of the Stanley Cup, head coach Bruce Cassidy is looking forward to evaluating the progress of Frederic, Senyshyn, and the rest of Boston's young players during training camp.
"They both got a look last year - obviously Trent got a longer one," said Cassidy, "so they have a bit of an idea of what's required. I think that always helps. Most guys on their second call-up do a little bit better because they're a little bit more prepared for what they need to do. I assume those two will be no different.
"As for our other young guys, we want internal competition and if they can push our veteran group, it's gonna make us that much better. That's what we're hoping for."